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Finding the Fourth Proportional to 428.43, 641.52 and 392.79

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Solution

The fourth proportional to 428.43, 641.52 and 392.79 is: 588.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.43 : 641.52 = 392.79 : x
  2. Step 2: Convert to fraction form
    428.43/641.52 = 392.79/x
  3. Step 3: Cross multiply
    428.43x = 641.52 × 392.79
  4. Step 4: Simplify right side
    428.43x = 251,982.64
  5. Step 5: Solve for x
    x = 251,982.64/428.43
  6. Step 6: Final answer
    x = 588.15

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.